Rigid tubing, usually made from aluminum, copper or various ductile alloys, are commonly used in the manufacture of fluid flow systems, for example evaporators and compressor cores for cooling, air conditioning and refrigeration systems. Finned tubing is usually mounted between two rigid end tubes. The two end tubes are baffled so as to direct fluid flow in a particular fashion through the finned tubing. One method of baffling includes inserting a disk inside the tubing from the tube end and then brazing the disk in place. Another method to create a baffle includes cutting the tube on its side and laterally sliding a disk or slug into the tube and brazing the slug or disk to the tube wall.
There are several problems associated with the present methods of forming the internal baffles described above. Firstly, the methods are slow and labor-intensive. The cutting of the tubes and disks, the inserting of the disk in its proper location and the brazing of the disk in place are not steps that are amenable to an automated operation. Secondly, it is difficult to verify the presence and quality of any baffles that lie between two end baffles. Two end baffles can be inspected from open ends of the tube; however, the intermediate baffles are concealed from view and must be tested rather than visually inspected. The exterior tube wall remains smooth and one cannot easily detect a baffle location. Thirdly, the presence of brazing introduces several problems. The brazing material is not integral with the tubing and may chip off or separate from the tubing thereby introducing particulate matter that floats through the system and that can pass and cause damage to fine machine parts of a compressor or pump. Brazing material may also contaminate oil if oil is used as a fluid within the tubing. The brazing material is often corrosive. It can form an acid within a fluid system and degenerate the interior walls of the evaporator and other interior parts of the fluid system. Finally, the brazing material is used not only as a seal but as a mounting device to secure the disc or baffle member in place in the tube.
What is desired is a baffle system which can be easily detected and visually checked from the outside and can withstand pressures that normally occur within compressor cores and under certain applications be brazeless or when used with brazing, the brazing material is used only as a sealant and not as a mount or fastening device.